Tomorrowland Winter is like very few festivals on the events calendar. Staged 2,000m above sea level at the picturesque Alpe d’Huez ski resort in the French Alps, the festival combines skiing, snowboarding, and electronic music, attracting 22,000 revellers to the slopes for a week of sun, snow, and immersive beats.
This year saw the introduction of several new stage concepts, including ORBYZ and a brand-new MainStage. The Cage stage also received a technological overhaul, featuring a reimagined Floating Sky and an enhanced sound design courtesy of Areal.
Throughout the week, over 150 artists, including the likes of Time, Axwell, Charlotte de Witte, Dimitri Vegas, Henri PFR, Lost Frequencies, MAALA, Novah, Ofenbach, Steve Angello, and many more, took the sound experience to unprecedented heights –figuratively and literally.
Pieter Doms, co-founder of Areal and NoizBoyz, is a freelance system technician and sound engineer with a long history of pioneering immersive audio. He’s worked independently and as part of the NoizBoyz collective. “By being both developer and user, you can ensure the perfect experience. It validates the work you’re doing,” Doms explained, speaking to TPi as the snow settled on the slopes.
Since 2016, Doms has led the sound design at Tomorrowland, constantly pushing the boundaries to create more immersive experiences with every event. In 2019, Areal’s initial prototype for the Upmix Engine was introduced at Tomorrowland Belgium. The experimental technology explored how to translate stereo sound into a live, immersive experience.
With the onset of the COVID-19 pandemic, live events came to a standstill, giving the team time to reflect rather than refine. Faced with the uncertainty of whether live experiences would ever fully return, Doms began asking a different question: how can we bring this immersive experience into people’s homes? This shift in thinking led to the invention of the SR1 headphone, designed to deliver spatial audio beyond the venue. Alongside the Upmix algorithm, which converts stereo into immersive audio in real time, both innovations are driven by his desire to make “spatial audio more accessible,” ultimately lowering the barriers to immersive sound in both live and studio environments.
Areal’s first product for the live events market, the Upmix Engine, laid the foundation for the company’s immersive ambitions, with the SR1 headphone emerging later as a natural extension into the studio space. “It quickly became clear that the SR1 was capable of providing a much more accurate 3D soundscape than binaural audio,” he recalled. “While it proved to be a powerful tool for immersive monitoring and content creation, the Upmix Engine continued to evolve in parallel. The focus remained on refining it into a robust live solution, with the Upmix algorithm as an additional feature which could enhance the overall experience.”
Multiple prototypes and Tomorrowland festivals followed, each further refining the technology. “We discovered that using multiple speaker setups surrounding the audience gave us a much more even distribution of sound and a more focussed delivery. This approach reduced sound spill between stages and to neighbouring areas, making it easier to manage acoustically,” he explained.
Tomorrowland Winter marked the first time a production unit was used, as opposed to a prototype. “The algorithm is identical, but this was the first year every stage at the festival was powered by Areal,” Doms clarified.
A three-point main PA system behind the LED screens featured 30 L-Acoustics K1 and four K2 loudspeakers, augmented by eight flown KS28 subwoofers. The main stage also featured a four-point delay system, which included four L2 and four L2D boxes.
A secondary delay system contained 12 Kara II loudspeakers and a ground sub array of 32 KS28s. A DiGiCo Quantum 7 served as the FOH console, with system processing achieved through a DirectOut PRODIGY.MP, TiMax OutBoard, and, of course, the brand-new Areal Upmix Engine.
“We’ve expanded each year,” Doms stated, proudly. “At Tomorrowland Belgium, Areal covered nine out of the 13 stages, and at Tomorrowland Winter in France, where regulations are more stringent, our technology covered all the stages. The festival’s location within the village homes requires a particularly cautious approach to sound management.”
At the CORE stage, a six-point 270º immersive setup comprised two pairs of L-Acoustics L2 and L2D loudspeakers as the main system, along with eight A15 loudspeakers and 28 KS28 subwoofers. A DiGiCo SD12 and the Areal Upmix Engine ensured crystal-clear audio. Meanwhile, the Cage stage featured a four-point system with four L2D loudspeakers and 16 KS28 subwoofers, powered by the same DiGiCo Quantum 7 and Areal Upmix Engine at FOH. Doms is keen to move beyond an engineering perspective and focus on the creative potential of the technology.
“Of course, it’s an Upmix Engine – it converts audio. It can be used in conjunction with any immersive mixer like L-ISA, d&b Soundscape, or TiMax running in parallel,” he explained. “It can be used in any setup where more than two speakers overlap, providing more coherent and homogeneous speaker cooperation.”
Sound engineers are always keen to experiment, and Doms emphasises that Areal tries to provide guidance in the field. “The algorithm’s flexibility means that engineers can interpret and experiment with the Upmix Engine in various ways. It’s constantly evolving,” he said. “My colleague handles the early shift, and I mix in the evenings on the main stage using Areal.”
The numbers speak for themselves: “If you can achieve a great show peaking at 98.5 dB LAeq over 15 minutes, that’s impressive!”
Discussing the adoption of Areal technology in the field, Doms likened the transition for engineers to the shift from 4:3 to 16:9. “Suddenly, your side fills become much wider and more open, which makes the sound more enjoyable to listen to,” he explained.
However, mixing 2,000m above sea level is not without its challenges. As Doms recounted with a laugh: “One night we arrived to find snow on the FOH console. It certainly makes for an exciting experience.”
After the success of Tomorrowland Winter, Doms swapped the -20°C chill of the French Alps for the +20°C warmth of Miami, where he joined Hardwell for Ultra Festival, before gearing up for Tomorrowland Belgium 2026, where Areal will power nine stages.
Despite the shock to the system, Doms is proud of the achievements in Alpe d’Huez. “What’s great about Tomorrowland Winter is the camaraderie on the mountain. Artists perform afternoon shows on the slopes, and the next day they’re on the main stage. It’s one of those festivals where artists are more accessible, especially early in the season,” Doms reminisced, fondly. “It was a great opportunity to showcase Areal to artists and sound engineers.”
Words: Jacob Waite
Photos: Areal and Tomorrowland
